mirror of
https://github.com/KolibriOS/kolibrios.git
synced 2024-12-16 03:42:35 +03:00
72 lines
1.8 KiB
C
72 lines
1.8 KiB
C
/* s_scalbnf.c -- float version of s_scalbn.c.
|
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
|
*
|
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
|
* Permission to use, copy, modify, and distribute this
|
|
* software is freely granted, provided that this notice
|
|
* is preserved.
|
|
* ====================================================
|
|
*/
|
|
|
|
#include "fdlibm.h"
|
|
|
|
#ifdef __STDC__
|
|
static const float
|
|
#else
|
|
static float
|
|
#endif
|
|
two25 = 3.355443200e+07, /* 0x4c000000 */
|
|
twom25 = 2.9802322388e-08, /* 0x33000000 */
|
|
huge = 1.0e+30,
|
|
tiny = 1.0e-30;
|
|
|
|
#ifdef __STDC__
|
|
float scalblnf (float x, long int n)
|
|
#else
|
|
float scalblnf (x,n)
|
|
float x; long int n;
|
|
#endif
|
|
{
|
|
__int32_t k,ix;
|
|
GET_FLOAT_WORD(ix,x);
|
|
k = (ix&0x7f800000)>>23; /* extract exponent */
|
|
if (k==0) { /* 0 or subnormal x */
|
|
if ((ix&0x7fffffff)==0) return x; /* +-0 */
|
|
x *= two25;
|
|
GET_FLOAT_WORD(ix,x);
|
|
k = ((ix&0x7f800000)>>23) - 25;
|
|
}
|
|
if (k==0xff) return x+x; /* NaN or Inf */
|
|
k = k+n;
|
|
if (n> 50000 || k > 0xfe)
|
|
return huge*copysignf(huge,x); /* overflow */
|
|
if (n< -50000)
|
|
return tiny*copysignf(tiny,x); /*underflow*/
|
|
if (k > 0) /* normal result */
|
|
{SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;}
|
|
if (k <= -25)
|
|
return tiny*copysignf(tiny,x); /*underflow*/
|
|
k += 25; /* subnormal result */
|
|
SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23));
|
|
return x*twom25;
|
|
}
|
|
|
|
#ifdef _DOUBLE_IS_32BITS
|
|
|
|
#ifdef __STDC__
|
|
double scalbln (double x, long int n)
|
|
#else
|
|
double scalbln (x,n)
|
|
double x; long int n;
|
|
#endif
|
|
{
|
|
return (double) scalblnf((float) x, n);
|
|
}
|
|
|
|
#endif /* defined(_DOUBLE_IS_32BITS) */
|